Catheters in common use have one or more lumens that are insertible into humans or animals. Catheters are inserted into body cavities, ducts, or vessels to allow the passage of fluids or to distend a passageway. Catheters may be positioned in ducts or vessels using guide wires that are first inserted into the duct or vessel. One or more of the lumens may permit guide wires or similar strands that travel within, and relative to, the lumen.
In one application, a relatively long guide wire passes through the catheter and into the bile duct or pancreatic duct. The guide wire is positioned by an assistant at an end of a relatively long guide wire. A physician views the movement of the guide wire and directs the movement of the guide wire. Thus, the wire is positioned by the assistant under the guidance of the physician. In most cases, the physician is positioned between the assistant and the patient, as he holds the scope at approximately mid-catheter. For fine movements into the duct to cannulate, a physician may control the guide wire, but this process requires the physician and the assistant to swap positions, which may be inconvenient or may disturb the procedure. Access to the guide wire is at the end of the catheter where the assistant advances the wire into, and through, the lumen. After the wire is in place in the duct, the physician may continue to control the guide wire, or the physician may return control of wire management to the assistant, who holds the wire in place from the end of the catheter.
In another application, a relatively shorter guide wire passes through the catheter and into the bile duct or pancreatic duct. The guide wire is positioned by the physician from the time of insertion, during gross advancement of the guide wire and during fine positioning of the guide wire. A physician views the movement of the guide wire and personally directs the physical movement of the guide wire. In this “short wire” process, the physician typically controls the entire process.
In practice, neither the “short wire” nor the “long wire” process is completely satisfactory. The physician generally prefers that the assistant perform gross advancement of the guide wire, but the physician prefers to perform the finer moments of final positioning of the guide wire in the duct.